E1 = 181.8539	#keV
E = 185.7
E2 = 194.4018	
mu1 = 0.34986   #cm^-1
mu2 = 0.34064
mu = mu1 +  (E-E1) * (mu2 - mu1) / (E2 - E1)
print("{:.4e}".format(mu))